Chapter 2: This Vortal Coil 2

Eventually, antlions will be coming out of every possible crevice. We suggest setting up the turrets to their own passages and letting the fellow fighters have their own passage while you cover yet another. Some antlions will invariably skip past the turrets and/or your comrades, so always watch your back. If you get overwhelmed, backpedal away the enemies while firing.

Soon, a pack of Vorts will show up to help you out, which is convenient as the antlion rush intensifies soon after. The Vorts don't so much cover any specific passages—rather, they spread out and lay an amazing beat down on most every antlion that dares enter the bunker. You'll still need to watch your back and pick off any enemies that get through the cracks of the Vort defense.

Soon the antlion attack ends and the Vorts gather around Alyx. Follow the lone Vort that takes off into one of the adjacent passages. He'll clear the immediate way, but it's up to you to lead him into the tunnel to the right.